Stationary shredder ring for waste comminuting devices



Feb. 11, 1958 E. J. HAMMEs 2,822,988

STATIONARY SHREDDER RING FOR WASTE COMMINUTING DEVICES 2 Sheets-Shea? 1Filed Oct. '7, 1954 E. J. HAMMES Feb. 1l, 1958 STATIONARY SHREDDEIR RINGFOR WASTE COMMINUTING DEVICES 2 Sheets-Sheet 2 Filed oct. 7, 1954INVENTOR.

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United States Patent STATIONARY SHREDDER RING FOR WASTE COMMINUTINGDEVICES Ever J. Hammes, Racine, Wis.

Application October 7, 1954, Serial N o. 460,839 3 Claims. (Cl. 241-298)This invention relates to a stationary shredder ring for comminutingdevices commonly known as garbage' disposal units.

Since the commercial development based on Hammes Patent 2,225,171,numerous commercial devices have adopted the construction therein shownof an inserted hard cutting ring which co-operates with `a rotatableunit to cause comminution of waste material.

The present invention contemplates a shredder ring formed of anunusually hard material and having a design for most effective operationon material which comes in contact with it. The invention -alsocontemplates a close relationship with the rotor associated therewith toprovide most eiiicient cutting in either direction.

It is an object of the invention to provi-de a cutting ring whichprevents food waste from merely riding around on the rotor without beingacted on by the teeth provided to cut it'into small pieces.

. A further object is the provision of a shredder ring which has alongawearing characteristic and formed of a material liriwhich'the"'edges`ofthe cutting teeth have capacity for retaining theirsharpness in a manner far superior to that of previously usedconstructions.

Other objects of the invention and details of construction will beevident in the following description and claims.

Drawings accompany the invention, and the various views thereof may bebriefly described as:

Figure l, a sectional view of a waste disposal assembly showing the ringand rotor in position.

Figure 2, a bottom view of the shredder ring.

Figure 3, a top view of the shredder ring.

Figures 4, 5, 6 and 7, sectional views of the shredder ring on lines4-4, 5 5, 6--6, and 7-7 of Figure 2.

In the past, the shredder rings for Waste disposal units have been madefrom forgings or castings which must be subsequently heat treated andmachined before use. This heat treating in addition to being anexpensive operation has frequently resulted in distortion of the deviceto make it out of round or out of shape in the direction of the axis,and it has also sometimes resulted in hair-line cracks which, if notdetected, later develop into a aw and cause breakage which might resultin considerable damage to the complete machine. In fact, in some casesthese cracks would develop into an open flaw while the machines wereneatly stored ready for shipment.

In the present invention, the shredder ring is cast from the materialwhich produces extremely accurate castings and which is so hard that itmust be ground if there are any slight changes necessary in the shapeafter casting. No heat treating is necessary.

It is preferable that the stresses in the casting be relieved by heatingto a temperature of 425 F. for a matter of three or four hours, but nohigh heats are required and no quenching is required. The castings comeout with a Rockwell C hardness of 58 to 64 with a very dense grainstructure. In some cases, the stress relieving draw 2,822,988 'PatentedFei). 11, 195s er' 1C@ operation will bring the Rockwell hardness downto Referring to the drawings, the shredder ring is shown to have acylindrical base portion 10 topped by a frustoconical portionv12. Thereare actually four series of cutting teeth in the unit. The cylindricalportion has a series of vertically disposed teeth 16 separated by plainwall portions and having a double edge, that is, opposed edgesvertically disposed for a cutting operation. Spaces between the teethform passages for material to pass 'fromv the chamber above the rotor tobe later described to the chamber below the rotor A second series ofteeth is formed on the inner wall of the frusto-conical section and hasthree equally divided portions stepped downwardly toward each otherindicated at 20, 22 and 24. The tooth face 20 is substantially parallelwith the outer wall of the portion 12 while the tooth faces 22 and 24are substantially parallel with the axis of the ring. y i

The teeth 20, 22 andy 24 are eight in number and spaced equally aroundthe ring. Av third series of teeth are positioned adjacent the secondseries andare also eight i,r"1.number.. These teeth are composed of twovertically spaced= portions, one tooth 30 and a second tooth 32. Again,the top tooth 30 has a face substantially parallel with the outer wallof the conical portion whereas the face of the tooth 32 is substantiallyparallel to the axis, the teeth being arranged in stepped relation as inthe previous series.

It will be noted that the shoulder 34 between teeth 30 and 32 fallsaxially about the middle of the tooth 22 of the second series describedabove. A fourth shank tooth 40 illustrated in Figure 5 and also inFigure 2 has a triangular cross section, and the tooth extends parallelto the conical wall portion 12 from the top of the ring to thetermination shoulders 42 where terminates all of the top series of teethand where originates the series of teeth 16.

The ring is preferably formed with an outwardly extending flange portionS0 at the bottom which may be ground subsequent to the casting operationto provide a circular mounting Wall to be received in a supportinghousing shown at 60 in Figure 1. The ring is held in place by a tophousing 62 and a resilient ring 64 placed against the top of the ring toexert a downward force thereon and also serving to seal the top of thering with respect to the housing 62.

The shredder ring is used in connection with a rotor 70 described indetail in co-pending application Serial No. 460,840, led October 7,1954.

It is important that the outer diameter of the rotor have a dimensionabout 5%6 smaller than the root diameter of the teeth 16 of the lowerseries. The clearance around the rotor can be .005 to the inner diameterof the teeth. This latter dimension is shown at B in Figure 1. It isimportant also that the top of the blades 72,

'which are radial ribs on the top of the rotor 70, be spaced In theoperation of thedevice, it will be seen that food dumped into thehousing 62 will be carried around on the rotor 70 and forced intocontact with the various series of teeth described. The teeth aredesigned to be approximately rectangular in their outer surfaces so thatthey will cut regardless of which direction the rotor is operating.

The upper portion of the shredder ring, including the teeth 20, 2.2 and24 and the teeth 30 and 32 serve ask breakers for the material whichwill drop down and get cut into smaller and iiner pieces as it is forcedbetween the ring and the teeth 16, which are 36 in number around thelower portion of the ring. The triangular or diamondshaped tooth 40functions to get the food waste tumbling, that is, to force it away fromthe side Wall in case it becomes grooved to match thefteeth 20, 22, 24,30 and 32.

,t will thus be seen that therev isl above described a shredder ring andcombination rotor which will provide extremely efiicient cutting ineither direction and which is formed of a material which is veryresistant to Wear and breakage and corrosion.

rThe cutter ring is especially designed to prevent riding of thematerial and thus insures as short an operating cycle as possible withany particular quantity of material.

I claim:

l. A stationary shredder ring for use as a comminuting cutter for Wastedisposal units which comprises aV frusto'- conical section superimposedintegrally on a cylindrical section, each section having a series ofinternal teeth disposed axially thereof, the teeth in said upper sectionbeing approximately one-half in number to the teeth in the lower sectionand in which the teeth in both sections are axially disposed andprovided with circumferentially spaced cutting edges, said upper sectionhaving two series of teeth, one with three stepped tooth portions spacedsubstantially equally throughout the upper section and the other withtwo spaced tooth sections spaced substantially equally of the uppersection.

2. A stationary shredder ring for use as a comminuting cutter for wastedisposal units which comprises a frustoconical section superimposedintegrally on a cylindrical section, each section having a series ofinternal teeth disposed axially thereof, the teeth in said upper sectionbeing approximately one-half in number to the teeth in the lower sectionand in which the teeth in both sections are axially disposed andprovided with circumferentially spaced cutting edges, said upper sectionhaving two series of teeth, one with three stepped tooth portions spacedsubstantially equally throughout the upper section and the other withtwo spaced tooth sections spaced substantially equally of the uppersection, the upper tooth of each of the stepped series having a toothface which is substantially frustoconical with relation to the ring, andthe lowerteeth of each series having a tooth face which is substantiallyaxial in relation to the ring.

3. A stationary shredder ring for use as a comminuting cutter for wastedisposal units which comprises a frusto-conical section superimposedintegrally on a cylindrical section, cach section having a series ofinternal teeth disposed axially thereof, the teeth in said upper sectionbeing approximately one-half in number to the teeth in the lowersection, the shredder ring being completely formed of a cast nickelchromium white iron having the following components in the proportionsindicated, total carbon, 3.00 to 3.60, graphitic carbon, .10 maximum,silicon, .40 to .70, manganese, .40 to .70, sulphur, .15, phosphorous,.40, nickel, 4.00 to 4.75, chromium, 1.40 to 3.50, remainder, cast iron.

References Cited in the le of this patent UNITED STATES PATENTS1,184,058 Watson May 23, 1916 1,973,263 Mitchell et al. Sept. ll, 193417,988,910 Merica Jan. 22, 1935 2,322,058 Powers June 15, 1943 2,594,250Tranbarger Apr. 22, 1952 2,629,558 Miller Feb. 274, 1953 2,682,376 FrankJune 29, 1954

